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<title>ASN1_STRING_length</title>
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<ul id="index">
  <li><a href="#NAME">NAME</a></li>
  <li><a href="#SYNOPSIS">SYNOPSIS</a></li>
  <li><a href="#DESCRIPTION">DESCRIPTION</a></li>
  <li><a href="#NOTES">NOTES</a></li>
  <li><a href="#RETURN-VALUES">RETURN VALUES</a></li>
  <li><a href="#SEE-ALSO">SEE ALSO</a></li>
  <li><a href="#COPYRIGHT">COPYRIGHT</a></li>
</ul>

<h1 id="NAME">NAME</h1>

<p>ASN1_STRING_dup, ASN1_STRING_cmp, ASN1_STRING_set, ASN1_STRING_length, ASN1_STRING_type, ASN1_STRING_get0_data, ASN1_STRING_data, ASN1_STRING_to_UTF8 - ASN1_STRING utility functions</p>

<h1 id="SYNOPSIS">SYNOPSIS</h1>

<pre><code>#include &lt;openssl/asn1.h&gt;

int ASN1_STRING_length(ASN1_STRING *x);
const unsigned char * ASN1_STRING_get0_data(const ASN1_STRING *x);
unsigned char * ASN1_STRING_data(ASN1_STRING *x);

ASN1_STRING * ASN1_STRING_dup(ASN1_STRING *a);

int ASN1_STRING_cmp(ASN1_STRING *a, ASN1_STRING *b);

int ASN1_STRING_set(ASN1_STRING *str, const void *data, int len);

int ASN1_STRING_type(const ASN1_STRING *x);

int ASN1_STRING_to_UTF8(unsigned char **out, const ASN1_STRING *in);</code></pre>

<h1 id="DESCRIPTION">DESCRIPTION</h1>

<p>These functions allow an <b>ASN1_STRING</b> structure to be manipulated.</p>

<p>ASN1_STRING_length() returns the length of the content of <b>x</b>.</p>

<p>ASN1_STRING_get0_data() returns an internal pointer to the data of <b>x</b>. Since this is an internal pointer it should <b>not</b> be freed or modified in any way.</p>

<p>ASN1_STRING_data() is similar to ASN1_STRING_get0_data() except the returned value is not constant. This function is deprecated: applications should use ASN1_STRING_get0_data() instead.</p>

<p>ASN1_STRING_dup() returns a copy of the structure <b>a</b>.</p>

<p>ASN1_STRING_cmp() compares <b>a</b> and <b>b</b> returning 0 if the two are identical. The string types and content are compared.</p>

<p>ASN1_STRING_set() sets the data of string <b>str</b> to the buffer <b>data</b> or length <b>len</b>. The supplied data is copied. If <b>len</b> is -1 then the length is determined by strlen(data).</p>

<p>ASN1_STRING_type() returns the type of <b>x</b>, using standard constants such as <b>V_ASN1_OCTET_STRING</b>.</p>

<p>ASN1_STRING_to_UTF8() converts the string <b>in</b> to UTF8 format, the converted data is allocated in a buffer in <b>*out</b>. The length of <b>out</b> is returned or a negative error code. The buffer <b>*out</b> should be freed using OPENSSL_free().</p>

<h1 id="NOTES">NOTES</h1>

<p>Almost all ASN1 types in OpenSSL are represented as an <b>ASN1_STRING</b> structure. Other types such as <b>ASN1_OCTET_STRING</b> are simply typedef&#39;ed to <b>ASN1_STRING</b> and the functions call the <b>ASN1_STRING</b> equivalents. <b>ASN1_STRING</b> is also used for some <b>CHOICE</b> types which consist entirely of primitive string types such as <b>DirectoryString</b> and <b>Time</b>.</p>

<p>These functions should <b>not</b> be used to examine or modify <b>ASN1_INTEGER</b> or <b>ASN1_ENUMERATED</b> types: the relevant <b>INTEGER</b> or <b>ENUMERATED</b> utility functions should be used instead.</p>

<p>In general it cannot be assumed that the data returned by ASN1_STRING_data() is null terminated or does not contain embedded nulls. The actual format of the data will depend on the actual string type itself: for example for an IA5String the data will be ASCII, for a BMPString two bytes per character in big endian format, and for a UTF8String it will be in UTF8 format.</p>

<p>Similar care should be take to ensure the data is in the correct format when calling ASN1_STRING_set().</p>

<h1 id="RETURN-VALUES">RETURN VALUES</h1>

<p>ASN1_STRING_length() returns the length of the content of <b>x</b>.</p>

<p>ASN1_STRING_get0_data() and ASN1_STRING_data() return an internal pointer to the data of <b>x</b>.</p>

<p>ASN1_STRING_dup() returns a valid <b>ASN1_STRING</b> structure or <b>NULL</b> if an error occurred.</p>

<p>ASN1_STRING_cmp() returns an integer greater than, equal to, or less than 0, according to whether <b>a</b> is greater than, equal to, or less than <b>b</b>.</p>

<p>ASN1_STRING_set() returns 1 on success or 0 on error.</p>

<p>ASN1_STRING_type() returns the type of <b>x</b>.</p>

<p>ASN1_STRING_to_UTF8() returns the number of bytes in output string <b>out</b> or a negative value if an error occurred.</p>

<h1 id="SEE-ALSO">SEE ALSO</h1>

<p><a href="../man3/ERR_get_error.html">ERR_get_error(3)</a></p>

<h1 id="COPYRIGHT">COPYRIGHT</h1>

<p>Copyright 2002-2020 The OpenSSL Project Authors. All Rights Reserved.</p>

<p>Licensed under the OpenSSL license (the &quot;License&quot;). You may not use this file except in compliance with the License. You can obtain a copy in the file LICENSE in the source distribution or at <a href="https://www.openssl.org/source/license.html">https://www.openssl.org/source/license.html</a>.</p>


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